The present invention is generally directed to flexible coupling devices of the type that are adapted to connect the end of a first shaft with the end of a second shaft. Such coupling devices are used, for instance, to transmit rotary or torsional power from a driven rotating shaft to an adjacent non-driven shaft. The coupling devices also provide flexibility for interconnecting a pair of opposing shafts that are slightly out of alignment.
More particularly, the present invention is directed to a flexible coupling device having a "tire style" coupling element. These types of coupling devices typically include a pair of opposing hubs, each mounted to the end of a respective rotatable shaft. The hubs are connected by a flexible, circular coupling element generally having the shape of a tire. In order to connect the opposing hubs together, each side of the coupling element is mechanically clamped between one of the hubs and an internal clamp ring.
One example of a shaft coupling device as described above is disclosed in U.S. Pat. No. 4,536,170 to Downey, which is incorporated herein in its entirety by reference. In Downey, an elastomeric sheer shaft coupling is disclosed for connecting two rotatable shafts in an end-to-end relationship. The coupling includes hubs for mounting on the opposed ends of the shafts with a flexible element extending between the hubs. The flexible coupling element is reinforced with layers of fabric or cord interspersed in an elastomeric material. Further, the margins of the coupling element have a bead therein of elastomeric material that has a higher durometer value than that forming the body of the element. The bead and the fabric are included to reinforce the element and to prolong its effective life.
Prior art constructions of coupling devices incorporating "tire style" coupling elements have provided meritorious advances in devices used to connect the ends of opposing shafts. Besides connecting the shafts together, these types of devices can accommodate slight amounts of angular misalignment and/or parallel misalignment. The flexible coupling element also cushions shock loads, putting much less stress on the industrial machinery associated with the shafts. Further, the flexible coupling element can dampen torsional vibration caused by the various engines and motors used to drive the shafts.
Most tire style coupling elements, however, include a slit which completely severs the element. The slit is provided for allowing the coupling element to be placed over a pair of internal clamp rings when being secured to the opposing hubs. The slit, unfortunately, lowers the overall strength and reduces the maximum amount of speed and torque which may be placed on the coupling element.